While photographic film assemblages of the self-developing type have undergone a plethora of advances, there remain several areas which require further examination and development. First, with the increasing growth of digital printing on a variety of low-cost media, conventional photographic film assemblages employing relatively more expensive silver halide emulsions face significant competitive challenges. As a consequence, there is an even keener interest to reduce overall film costs. Such interests are even more pronounced in the area of self-developing film assemblages since the latter include more complex chemistry, as well as the complexity of the film construction required for capturing and processing images in a self-contained manner. Further, it is highly desirable to allow the user to remove unneeded portions of the latter type of film unit so that only the image bearing portion remains, thereby giving the impression of a conventional 35 mm print or digital print.
Photographic film assemblages of the self-developing type are well-known in the photographic arts and have been described in numerous patents, such as, for example, U.S. Pat. Nos.: 2,612,450; 2,983,606; 3,345,163; 3,362,819; 3,415,644; 3,473,925; 3,594,164; 3,594,165; and, 5,888,693 issued to Polaroid Corporation, Cambridge, Mass., USA. In general, these film constructions employ sophisticated package constructions comprising several distinct components united together in a relatively complex approach in order to achieve a multiplicity of image capturing and processing functions. For instance, the film assemblage allows storing, spreading, collecting, and retaining of the processing fluid that initiates photographic development of latent images. In brief, each film unit generally includes a photosensitive sheet that captures latent images, a positive receiving sheet for producing the developed image, and a chemical reagent system including the processing fluid. The processing fluid is stored in a rupturable photographic processing fluid supply reservoir or xe2x80x9cpodxe2x80x9d for release and distribution between the photosensitive and positive sheets for initiating diffusion transfer, and a fluid trap is used to subsequently capture the processed fluid within the confines of the film unit. The film unit functions to safely store the sensitive chemical compositions during handling and processing, to insure that such chemicals effect the desired development without degradation, and to prevent leakage and/or contamination of the chemicals prior to use.
Photographic film assemblages of the self-developing type are generally categorized as so-called xe2x80x9cpeel-apartxe2x80x9d versions, and xe2x80x9cintegralxe2x80x9d versions. In the peel-apart version, provision is made for exposing a photosensitive sheet that is brought together, in overlying relationship, with an image receiving sheet carrying a rupturable reservoir or xe2x80x9cpodxe2x80x9d of processing fluid. The sheets pass through a pressure applying assembly comprising a pair of juxtaposed rollers that rupture the container and spread the fluid so as to initiate development of the latent exposed image. Excess fluid that passes between the sheets is then collected by a fluid trap. The user peels off the image bearing portion, while the pod and trap areas remain associated with the film assemblage.
Integral film units such as described in commonly assigned U.S. Pat. Nos. 3,415,645; 3,695,884; and 3,833,382, are considered self-contained in that the rupturable container or pod, imaging bearing area, and fluid trap remain together, or integral as a unit, both prior to and after exposing. Processing is carried out by passing the film unit through processing rollers that rupture the pod and distribute the processing fluid to initiate development. The trap subsequently captures excess processing fluid. Therefore, the film unit that emerges from a camera, for instance, is self-contained. U.S. Pat. No. 5,888,683 describes another example of a self-contained film assemblage in the form of an elongated strip that includes a plurality of film units or frames carried thereby; whereby each of the units is separable relative to the others.
For a variety of reasons, however, it is desirable to allow the user of integral film units to retain the image bearing portion free of the spent pod and associated trap. Efforts to achieve such pod and trap removal have been described. For example, commonly-assigned U.S. Pat. No. 2,634,886 discloses a peel-apart type of film assemblage which utilizes semi-perforations that allow manual severance of the positive print from adjacent areas of the film assemblage including the pod and trap. U.S. Pat. No. 3,804,626 discloses a film assemblage wherein the pod and trap are separated from the film unit; and wherein a processing fluid activated adhesive serves to seal the trailing end of the film unit. U.S. Pat. No. 4,693,963 uses perforations between the positive print and the pod and trap so as to allow for manual separation of the latter so that undesired elements of the film assemblage may be discarded. The aforementioned patent also teaches sealing along the open edges of the film resulting from detachment. Sealing may be accomplished by a pressure sensitive or processing fluid adhesive on one or more of the mutually facing surfaces of the open edges. Consequently, integrity of the developed film unit is maintained along with prevention of processing fluid leakage.
Thus, while efforts along the lines indicated above have been made, there is, nevertheless, a continuing need to improve upon the ease and reliability of removing from such self-developing film assemblages, the fluid pod, and fluid trap portions in a manner that substantially minimizes and/or seals against leakage of processing fluid, either prior to or after film processing.
Further, currently-available self-developing film assemblages lack the ability to be universally-utilized in a wide variety of differing camera types. Each self-developing film unit typically possesses a different construction in order to be used with a particular commercial line of self-developing cameras. It will be appreciated, therefore, that each camera line typically utilizes a different film construction.
Thus, despite the multiplicity of known self-developing film constructions and their commercial success, there is, nevertheless, a continuing desire to simplify these constructions and to reduce material and manufacturing costs, while concomitantly retaining their high degree of integrity and reliability. Accordingly, there remains a desire to develop a single, unified film architecture that is highly versatile from the standpoint of being capable of being used in a variety of existing and future self-developing camera lines of various film sizes. In addition, there also remains a desire to be able to remove unneeded film parts, such as pod and fluid collecting trap segments for purposes of presenting the resulting developed image area as a 35 mm-style print or as a digital print.
Also, as self-developing film assemblages are subjected to a relatively-high degree of stress as they are pulled through the camera""s mechanism (e.g., rollers) during the development process, they must possess both mechanical and structural integrity. There continues to be a need for the development of such film assemblages.
The present invention relates to a film assemblage of the self-developing type comprising a first sheet and a second sheet in juxtaposed relationship to one another. Each of the sheets contains a plurality of exposure cut-outs at spaced-apart intervals. Portions of the first and second rectangular sheets which separate individual exposure cut-outs contain a frangible line running in a direction perpendicular to the major axis of the rectangular sheet. The film assemblage further comprises a plurality of positive receiving sheets, a plurality of negative or photosensitive sheets, an elastic carrier sheet, a plurality of photographic processing fluid supply pods and a plurality of photographic processing fluid collection traps. The relationship between these elements in the film assemblage of the present invention is fully described in the Description of Preferred Embodiments section which follows.
Briefly, the first and second rectangular sheets are aligned with exposure cut-outs and frangible lines in-register thereby forming a series of exposure frames separable along frangible lines. Each of the plurality of in-register exposure cut-outs, or exposure frames, has a leading edge and a trailing edge which are defined with respect to the order in which the edges pass a set of spread rollers in the camera in which the film unit is loaded. The leading edge of each exposure frame contains a channel in communication with a photographic processing fluid supply pod positioned between the first and second sheets, and the trailing edge of each exposure frame contains a channel in communication with a photographic processing fluid collection trap positioned between the first and second rectangular sheets. Each exposure frame is backed on one side by a positive receiving sheet, and on the other side by a negative or photosensitive sheet.
An elastic carrier sheet is adhered to each negative or photosensitive sheet, and to inter-exposure frame portions of the rectangular sheet to which the negative or photosensitive sheet is attached. Frangible lines fall between each point of adherence to a negative or photosensitive sheet, and adjacent points of adherence to inter-exposure frame portions of the rectangular sheets.